Data access device and access error notification method

A data access device comprising:

• a bus slave;
• a first bus master and a second bus master each of which notifies the bus slave of a bus request and makes an access to the bus slave;
• and
• a common bus to which the bus slave, the first bus master, and the second bus master are coupled,
• wherein the first bus master occasionally makes a speculative access to the bus slave,
• wherein the second bus master performs no speculative access to the bus slave,
• wherein the bus request includes mode information for selecting whether error notification for an access is performed by the bus slave or a bus master,
• wherein, in a case where the mode information indicating that error notification is performed by the bus slave is included in the bus request, when an error for the access in the bus request has occurred, the bus slave performs error notification,
• wherein, in a case where the mode information indicating that error notification is performed by the bus master is included in the bus request, when an error for the access in the bus request has occurred, the bus slave sends error information to the first bus master or the second bus master,
• wherein, in a case of making a speculative load access, the first bus master makes the bus request include the mode information indicating that error notification is performed by the bus master,
• wherein, in a case where execution of an instruction of the speculative load access has been fixed and the error information for the load access has been received from the bus slave, the first bus master performs error notification, and
• wherein, in a case of making the access to the bus slave, the second bus master makes the bus request include the mode information indicating that error notification is performed by the bus slave.

An access error notification method comprising:

• issuing a bus request including mode information for selecting error notification for an access is performed by a bus slave or a bus master, and making an access to the bus slave, by the bus master;
• in a case where the mode information indicating that error notification is performed by the bus slave is included in the bus request, when an error for the access in the bus request has occurred, notifying an error processing unit that performs a predetermined process for the error of the error, by the bus slave;
• in a case where the mode information indicating that error notification is performed by the bus master is included in the bus request, when an error for the access in the bus request has occurred, sending error information to the bus master, by the bus slave;
• in a case where a speculative load access is made, making the bus request include the mode information indicating that error notification is performed by the bus master, by the bus master;
• and
• in a case where execution of an instruction of the speculative load access has been fixed and the error information for the load access has been received from the bus slave, performing error notification to the error processing unit, by the bus master.